977 resultados para Cluster size
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Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five trees (>17 m tall) of different species were selected. Stomatal type, density (S D), size (S S) and stomatal distribution on the leaf surface were determined using nail polish imprints taken from both leaf surfaces. Irrespective of tree species, stomata were located only on the abaxial surface (hypostomaty), with large variation in both S D and S S among species. S D ranged from 110 mm-2 in Neea altissima to 846 mm-2 in Qualea acuminata. However, in most species S D ranges between 271 and 543 mm-2, with a negative relationship between S D and S S. We also found a positive relationship between S D and tree height (r² = 0.14, p < 0.01), but no correlation was found between S D and leaf thickness. The most common stomatal type was anomocytic (37%), followed by paracytic (26%) and anisocytic (11%). We conclude that in Amazonian tree species, stomatal distribution on the leaf surface is a response most likely dependent on the genetic background of every species, rather than a reaction to environmental changes, and that somehow S D is influenced by environmental factors dependent on tree height.
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Objetivos Desenvolver e avaliar uma tipologia binária de alcoolistas. Métodos Analisados registros de 329 alcoolistas acompanhados em estudo prospectivo e observacional. Análise de Correspondência foi aplicada para selecionar o menor número de variáveis capazes de representar a máxima variabilidade dos sujeitos; Análise de Cluster para identificar dois subtipos; e Análise Heurística para organizar as variáveis selecionadas em grupos de sentido. Análises Bivariadas foram utilizadas para testar possíveis associações com 51 variáveis demográficas ou clinicamente relevantes. Resultados A Análise de Correspondência selecionou 20 variáveis, posteriormente categorizadas em três grupos de sentidos por meio de Análise Heurística: “comportamentos”, “crenças” e “sentimentos”. Os pacientes do subgrupo 1 possuem perfil de maior gravidade clínica, psicopatológica e social. Sentimentos e crenças identificados se associaram a variáveis de consumo e recaída e os comportamentos com repercussão social. Conclusões Os resultados deste estudo permitem supor que a tipologia aqui apresentada possa contribuir para o tratamento desses subtipos de alcoolistas identificados por meio de estratégias teórico-práticas adaptadas às necessidades desses sujeitos.
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The suitability of a total-length-based, minimum capture-size and different protection regimes was investigated for the gooseneck barnacle Pollicipes pollicipes shellfishery in N Spain. For this analysis, individuals that were collected from 10 sites under different fishery protection regimes (permanently open, seasonally closed, and permanently closed) were used. First, we applied a non-parametric regression model to explore the relationship between the capitulum Rostro-Tergum (RT) size and the Total Length (TL). Important heteroskedastic disturbances were detected for this relationship, demon- strating a high variability of TL with respect to RT. This result substantiates the unsuitability of a TL-based minimum size by means of a mathematical model. Due to these disturbances, an alternative growth- based minimum capture size of 26.3 mm RT (23 mm RC) was estimated using the first derivative of a Kernel-based non-parametric regression model for the relationship between RT and dry weight. For this purpose, data from the permanently protected area were used to avoid bias due to the fishery. Second, the size-frequency distribution similarity was computed using a MDS analysis for the studied sites to evaluate the effectiveness of the protection regimes. The results of this analysis indicated a positive effect of the permanent protection, while the effect of the seasonal closure was not detected. This result needs to be interpreted with caution because the current harvesting based on a potentially unsuitable mini- mum capture size may dampen the efficacy of the seasonal protection regime.
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Dissertação de mestrado em Economia Industrial e da Empresa
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OBJECTIVE - Angiotensin-converting enzyme inhibitors (ACEIs) have gained importance in preventing or attenuating the process of ventricular remodeling after myocardial infarction. The significance of infarct size in regard to the response to ACEIs, however, is controversial. This study aimed to analyze the effects of lisinopril on mortality rate, cardiac function, degree of cardiac hypertrophy and fibrosis in rats with different infarct sizes. METHODS - Lisinopril (20 mg/kg/day) dissolved in drinking water was administered to rats immediately after coronary artery occlusion. After being sacrificed, the infarcted animals were divided into two groups: one group of animals with small infarcts (< 40% of the left ventricle) and another group of animals with large infarcts (> 40% of the left ventricle). RESULTS - The mortality rate was 31.7% in treated rats and 47% in the untreated rats. There was no statistical difference between the groups with small and large infarcts in regard to myocardial concentration of hydroxyproline. In small infarcts, the treatment attenuated the heart dysfunction characterized by lower levels of blood pressure and lower values of the first derivative of pressure and of the negative derivative of pressure. The degree of hypertrophy was also attenuated in small infarcts. In regard to large infarcts, no differences between the groups were observed. CONCLUSION - Treatment with the ACEIs had no effect on mortality rate and on the amount of fibrosis. The protective effect of lisinopril on heart function and on the degree of hypertrophy could only be detected in small infarcts
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Dissertação de mestrado em Comunicação, Arte e Cultura
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Magdeburg, Univ., Fak. für Naturwiss., Diss., 2010
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Background: The effects of modern therapy on functional recovery after acute myocardial infarction (AMI) are unknown.Objectives:To evaluate the predictors of systolic functional recovery after anterior wall AMI in patients undergoing modern therapy (reperfusion, aggressive platelet antiaggregant therapy, angiotensin-converting enzyme inhibitors and beta-blockers).Methods:A total of 94 consecutive patients with AMI with ST-segment elevation were enrolled. Echocardiograms were performed during the in-hospital phase and after 6 months. Systolic dysfunction was defined as ejection fraction value < 50%.Results:In the initial echocardiogram, 64% of patients had systolic dysfunction. Patients with ventricular dysfunction had greater infarct size, assessed by the measurement of total and isoenzyme MB creatine kinase enzymes, than patients without dysfunction. Additionally, 24.5% of patients that initially had systolic dysfunction showed recovery within 6 months after AMI. Patients who recovered ventricular function had smaller infarct sizes, but larger values of ejection fraction and E-wave deceleration time than patients without recovery. At the multivariate analysis, it can be observed that infarct size was the only independent predictor of functional recovery after 6 months of AMI when adjusted for age, gender, ejection fraction and E-wave deceleration time.Conclusion: In spite of aggressive treatment, systolic ventricular dysfunction remains a frequent event after the anterior wall myocardial infarction. Additionally, 25% of patients show functional recovery. Finally, infarct size was the only significant predictor of functional recovery after six months of acute myocardial infarction.
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Background:Cardiovascular urgencies are frequent reasons for seeking medical care. Prompt and accurate medical diagnosis is critical to reduce the morbidity and mortality of these conditions.Objective:To evaluate the use of a pocket-size echocardiography in addition to clinical history and physical exam in a tertiary medical emergency care.Methods:One hundred adult patients without known cardiac or lung diseases who sought emergency care with cardiac complaints were included. Patients with ischemic changes in the electrocardiography or fever were excluded. A focused echocardiography with GE Vscan equipment was performed after the initial evaluation in the emergency room. Cardiac chambers dimensions, left and right ventricular systolic function, intracardiac flows with color, pericardium, and aorta were evaluated.Results:The mean age was 61 ± 17 years old. The patient complaint was chest pain in 51 patients, dyspnea in 32 patients, arrhythmia to evaluate the left ventricular function in ten patients, hypotension/dizziness in five patients and edema in one patient. In 28 patients, the focused echocardiography allowed to confirm the initial diagnosis: 19 patients with heart failure, five with acute coronary syndrome, two with pulmonary embolism and two patients with cardiac tamponade. In 17 patients, the echocardiography changed the diagnosis: ten with suspicious of heart failure, two with pulmonary embolism suspicious, two with hypotension without cause, one suspicious of acute coronary syndrome, one of cardiac tamponade and one of aortic dissection.Conclusion:The focused echocardiography with pocket-size equipment in the emergency care may allow a prompt diagnosis and, consequently, an earlier initiation of the therapy.
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Bundle of capillaries, drying kinetics, continuous model, relative permeability, capillary pressure, control volume method
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Magdeburg, Univ., Fak. für Naturwiss., Diss., 2009
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Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2012
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Ziel der Arbeit war es, den Wirtschaftsraum Blankenburg (Harz) durch die Bildung und Förderung von gewerblichen Clustern attraktiver zu gestalten. In diesem Rahmen wurde zunächst die Entwicklung von Gewerbe- und Industrieflächen mithilfe der Bauleitplanung in Theorie und Praxis beschrieben. Die anschließende Untersuchung des Bundeslandes Sachsen-Anhalt und im speziellen der Stadt Blankenburg (Harz) bildeten die Datengrundlage für die weiteren Arbeitsschritte. Um die Ergebnisse dieser Standortanalyse in einen direkten Zusammenhang mit tatsächlichen Eindrücken der ansässigen Unternehmen bringen zu können, wurde eine schriftliche Unternehmensbefragung durchgeführt. Diese thematisierte vor allem die Einschätzung der Standortfaktoren in Blankenburg (Harz). Die im Zwischenfazit beschriebene Wertung, dass die Stadt derzeit nur wenige Anreize für Unternehmensneuansiedlungen bietet, war Ausgangspunkt für die Theorie der Clusterpolitik. Dabei wurden zunächst gewerbliche Cluster aus den ansässigen Unternehmen gebildet. Daraus resultierten die Wirtschaftsbereiche, deren Unternehmen für eine Ansiedlung in Blankenburg besonders in Frage kommen. Da diese Betriebe feste Anforderungen an Gewerbe- oder Industrieflächen in Bezug auf die Größe, die planungsrechtlichen Beschränkungen und die infrastrukturelle Anbindung stellen, konnten die vorhandenen Freiflächen im Rahmen einer Mikroanalyse hinsichtlich ihrer Eignung für Neuansiedlungen untersucht werden.
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n.s. no.46(1988)
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n.s. no.16(1983)